I just bought a 2003 G35. It have the codes above. These codes are no can communication. Both the slip and the AT light are on all the time as soon as I turn it on. It is also on limp mode or so it seems because it is on 2nd gear and wont go above that, also the gear selector screen is in blank in both auto and manual mode. I checked under the battery and found some interesting things. First , the IPDM starter relay have been bypassed and a direct cable put on it to the starter. It seems they also did some repairs on some of the battery white cables and spliced a few. There is also a green/red cable from the main harness that seems a little frayed and I identified as part of the can bus communication.There is another black cable that is broken , but I can not find the other end or where it came from. It is a total mess. They did not shield any of this cables after the sorry intent of repair and the water drain under the battery was clogged. I suspected at the beginning that the TCM was bad due to the AT light on all the time, but now I think this is something else. According to the guy that sold it to me, they only (repaired a battery cable) before. Now he could not give me a lot of info because this car was from his son. He said that this "repair" was done around october, and he forgot that he already had txt me that the car was garaged since october when I first contacted him, so my theory is as follows. I guess that this car had starting problems at first, and was taken to a half a cent mechanic that found that the starter relay was bad, and instead of properly replacing it, decided to do the dirty started bypass. He did not even fit it properly,the cable was basically hanging from one of the legs of the relay.I think this either shorted the ipdm or that the car ipdm or ecu registered the bad relay and entered limp mode. I guess some of the cables of the can bus are fried or maybe the ipdm is not communicating. I will know when I do some more troubleshooting. I am going to get this relay new first and then see if it starts with it, and if it does not then open the ipdm and see if there is water damage. Infiniti did a terrible job of putting that IPDM in that area with the small drain that clogs easily. I have read a lot about water damage in that area and dead IDPM. The car also have 165k. I hope it is only repairable wiring and not a real transmission problem. Other than that , they told me they had repaired the air conditioning and I noted it does not have the original radio console and it seems that they used an aftermarket console to eliminate the radio console. The car starts and the engine sounds great with the jumper, but that is damaging everything else I think. If anyone have some pointers or help regarding this or have been thru this road , please chime in and give me some advice. Thanks.